IPv4 is the original version of the Internet Protocol. It uses 32-bit addresses expressed in dotted decimal notation like 192.168.1.1. Addresses are divided into network and host parts based on the subnet mask. While IPv4 was widely adopted, it has limitations like a finite address space and no inherent support for mobility or security. Possible solutions include CIDR and NAT to extend the address space, but a new protocol, IPv6, was developed to overcome IPv4's limitations.

1. IPv4 ADDRESSING

2. IP ADDRESS
-IP Address stands for "Internet Protocol Address". An IP address is a technique number provided to each an
every devices.
It is in the form of integric number which is separated by dot(.)
Example: 192.168.10.26
Addressing:
* IP(Logical)
* MAC(Physical)
* Two types of IP Address :
IPV4 and IPV6
•IP addresses can be classified into two categories: private and public.
- Private IP addresses are used within an organization's internal network and are not routable over the internet.
They allow multiple devices to share a single public IP address.
- Public IP addresses, on the other hand, are globally unique and can be accessed over the internet. They are
provided by Internet Service Providers (ISPs) and allow devices to communicate with other devices on the
internet.

3. What is IPv4?
IP stands for Internet Protocol and v4 stands for Version Four (IPv4). IPv4 was the primary version brought into
action for production within the ARPANET in 1983. IP version four addresses are 32-bit integers which will be
expressed in decimal notation. Example- 192.0.2.126 could be an IPv4 address.
Parts of IPv4
* Network part: The network part indicates the distinctive variety that’s appointed to the network. The network
part conjointly identifies the category of the network that’s assigned.
* Host Part: The host part uniquely identifies the machine on your network. This part of the IPv4 address is assigned
to every host. For each host on the network, the network part is the same, however, the host half must vary.
* Subnet number: This is the nonobligatory part of IPv4. Local networks that have massive numbers of hosts are
divided into subnets and subnet numbers are appointed to that.
Sure, let's break down an IPv4 address into its network and host parts, and then calculate the subnet number using
an example.
To calculate the network part and host part:
1. Identify the subnet mask associated with the network. The subnet mask determines how the IP address is divided
into network and host parts.
2. Perform a bitwise AND operation between the IP address and the subnet mask to find the network part.
3. The remaining bits after the AND operation represent the host part.

4. Characteristics of IPv4
*IPv4 could be a 32-Bit IP Address.
*IPv4 could be a numeric address, and its bits are separated by a dot.
*The number of header fields is twelve and the length of the header
field is twenty.
*It has Unicast, broadcast, and multicast style of addresses.
*IPv4 supports VLSM (Virtual Length Subnet Mask).
*IPv4 uses the Post Address Resolution Protocol to map to the MAC
address.
*RIP may be a routing protocol supported by the routed daemon.
*Networks ought to be designed either manually or with DHCP.
*Packet fragmentation permits from routers and causing host.

5. Ipv4 address notation
There are three notations to show an IPv4 address which
are as follows −
*binary notation (base 2)
*dotted-decimal notation (base 256)
*hexadecimal notation (base 16)
The three notations to show an IPv4 address are
diagrammatically represented below
EXAMPLE:
*Binary Notation (Base 2):
Decimal 42 in binary is represented as 101010.
Here's the computation:42 divided by 2 is 21 with a
remainder of 0.21 divided by 2 is 10 with a remainder of
1.10 divided by 2 is 5 with a remainder of 0.5 divided by 2
is 2 with a remainder of 1.2 divided by 2 is 1 with a
remainder of 0.1 divided by 2 is 0 with a remainder of
1.Reading the remainders in reverse order gives 101010.
*Dotted-Decimal Notation:
Decimal 42 remains the same in dotted-decimal notation:
42.0.0.0.There's no computation involved here; it's a
direct conversion where each byte is represented by a
decimal number separated by dots.
*Hexadecimal Notation (Base 16):
Decimal 42 in hexadecimal is represented as 2A.Here's
the computation:42 divided by 16 is 2 with a remainder of
10 (which is represented as 'A' in hexadecimal).2 divided
by 16 is 0 with a remainder of 2.So, reading the
remainders in reverse order gives 2A.

6. *Advantages of IPv4
•Widely supported
•Shorter the sweeter (header)
•Support of All OS
•All Commonly used protocols are supported
*Disadvantages of IPv4
• Limited address space
• Flat routing infrastructure
• Configuration
Security
•Quality of service (QoS)
Mobility

7. Limitations of IPv4
*IP relies on network layer addresses to identify end-points on network,
and each network has a unique IP address.
*The world’s supply of unique IP addresses is dwindling, and they might
eventually run out theoretically.
*If there are multiple host, we need IP addresses of next class.
*Complex host and routing configuration, non-hierarchical addressing,
difficult to re-numbering addresses, large routing tables, non-trivial
implementations in providing security, QoS (Quality of Service), mobility
and multi-homing, multicasting etc. are the big limitation of IPv4 so that’s
why IPv6 came into the picture.

8. Limitations and some solutions of
IPv4:
*Limitations
•Exponential growth since 199|
large routing tables
•Need for simpler configuration
•Requirement for security at the IP level
•Need for better support for real-time delivery of dataalso
called quality of service (QoS)
*Possible solutions
•Class to classless (CIDR)
•NetworlkAddress Translation (NAT)
•Separated attached component:IPsecV4, IP mobile, ...